Air-brake apparatus.



H. M. -1 .`MYURPH'Y.

AIR BRAKE APPARATUS.

APPLICATION FILED APB.. 4, 1908. 91 2,3 1 7, Patented Feb. 16, 1909.

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Allorney l nu: Nomus Fsrsre's co.. WASHINGTON, s. c.

H. M. P. MURPHY.

AIB. BRAKE APPARATUS.

APPLIUATION FILED APRA, 190s.

91 2,3 17. Patented Feb. 16, 1909.

2 SHEETS-SHEET 2.

Tus NoRlus PETERS co, yusmgmnxl, D. c,

NETE@ STATE@ PATENT @FICE HOWARD M. l. MURPHY, OFYITTSBURG,PENNSYLVANIA, ASSIGNOR OF ONE-FOURTH TO L. H. BOMAN, Or MUN? NERY, OFPITTSBURG, PENNSYLVANIA.

ALL, PENNSYLVANA, AND ONE-EIGHTH T JOSEPH M. FLAN- A1B-BRAKE APPARATUSPatented Feb. 16, 1909.

Application led April 1908. Serial No. LL125,196.

To all @clio-m it muy concern:

Be it known that l", ilout-inn M. P. MUR- rrir, a resident of Pittsburg,in the county orlllegheny and State of Pennsylvania,

have invented certain neuT and uset'ul lmproveinents in Air-BrakeApparatus; and

1 do hereby declare the following to be a ifull, clear, and exactdescription of the invention, such as Will enable others skilled in theart to which it appertains to make and use the same.

rllhis invention relates to improvements in air brake apparatus and moreparticularly to a triple valve mechanism.

@ne object of my present invention is to so construct. a triple valvemechanism as to enhance the emciency of the same and insure the accurateoperation in eii'ecting the application and release of the brakes underall conditions and also to cause the proper recharging ot' the auxiliaryreservoirs.

A further object is to provide improved means for insuring etliciencyand accuracy in both service and emergency applications ot the brakesand to provide improved means tor ellecting a graduated release of thebrakes.

A further object is to so construct a triple valve mechanism that itshall be very sensitive to variations of train pipe pressure, re-

gardless ot the position on a long or a short train, at which saidmechanism may be located. Y

A further object is to improve in other respects, the construction oftriple valve mechanism so as to avoid possibility of imperfect or faultyoperation of the brakes and also to provide means for the maintenance ofbrake cylinder pressure in spite of leakage.

lilith these objects in view, the invention consists in certain novelfeatures of construction and combinations and arrangements of partshereinafter set forth and pointed out in the claims.

.l'n the accompanying drawings Figure 1 is a sectional vieiv of triplevalve mechanism embodying my improvements, the parts being shoivn inrelease position; Fig. 2 is a similar vier`r With the parts in releaselap position. Fig. 3 is a view showing the parts in the emergencyposition; Fig. 4 a plan view of the main slide valve seat: Fig. 5 is atop plan view of the main slide valve, and Fig. 6 is al top plan view ofthe graduating valve..

In the sectional views,

the sections of the slide valves and the valve seat are taken on thelines m-, 3/-y, and

respectively of Figs. 4, 5, and 6.

1 represents a casing, one head 2, of which constitutes one end of ingel a valve chamber 5 A bushcasing and aliords which communicates 'at achamber 3. is located Within the one end with the chamber 3. A piston 6is located within the chamber 3 and is provided with a roo 7 foroperating slide valves R and S in the valve chamber 5, as hereinafterdescribed.

Ducts 8`9 are provided for conducting train pipe fluid to the chambers`3-5 a nd the chamber tion of the chamber 8 to ton W 5, together withthat porthe left of the pisill constitute What may be convenientlytermed, a contiolling space At the uncture or the ducts S and 9 a checkvalve 10 is loc ated, and is pressed upon its .seat by means of a lightspring 11, said valve being adapted to prevent a backward passage oftluid from the controlling space, through the duct 9 to the train pipe.

tutes A duct 12 constia continuation of the train pipe duct 8 and is intree communication at one end with in a s a duct 13 which terminates ina port f eat T for the main slide valve S. The

port f and ducts 13, 1Q and 8 thus constitute a free path for fluid fromthe valve chamber 5 (which constitutes a portion of the controllingspace) to the train pipe under certain c other tion of the mechanism) bonditions, but such path is closed under conditions (as in emergencyposif the covering ot' the `port f by the main slide valve S.

Auxiliary reservoir fluid is admitted to the chamber 5 (at the righthand side of the piston 6 therein) through a port 14 Which receives suchfluid through ports 15 in a hollowv enlaroement 16, from voir duct 1T.

to eli voir,

an auxiliary reserlVhen the parts are in position ect a recharge of theauxiliary reserthe piston 6 Will uncover a duct 1S in the Wall ofchamber 3, so that train pipe fluid can How from the controlling spaceat it is desirable flow at certain times to restrict the of auxiliaryreservoir fluid from the auxiliary right of the piston 6 and at othertimes to permit free communication between the chamber 3 vand theauxiliary duct. To accomplish this, a rod 21 is employed, said rod beingprovided with a contracted portion 22 which, when in the position shownin Fig. l, will permit a free communication between the chamber 3 andthe auxiliary reservoir duct. Tt is apparent however, that when thelarger portion 23 of the rod is disposed in the port 14 and between theports 15, the passage for auxiliary 'fluid to the chamber 3 at the rightof the piston will be restricted. The rod Q1 passes through a gland Q4secured to the piston G and enters a socket 9.5 in the piston rod 7, themovement of said rod 21 in one direction being limited by the engagementof a head 2G thereon with the gland 24e. The rod Q1 is normally pressedin this direction by a spring 9.7 located in the socket 25, and said rod21 is movable in the other direction for effecting a slight movement ofthe piston by the action of the spring, by engagement with an abutmentQS aiiorded by the enlargement 16.

A duct 29 leads to the brake cylinders and communicates with a chamber30. From this chamber, a duct 31 extends to the valve seat T, so as tocommunicate at one end with a port a therein. A check valve 32 closesthe other end of the duct 31 so as to prevent a back Iiow of brakecylinder tluid through the duct 31 under certain conditions. A duct 33also communicates with the chamber 30 so as to, in eiiiect, constitutean extension ot' the brake cylinder duct 29. The duct 33 is adapted tocommunicate, through a valve chamber 33, with a duct 33a, and the upperend of the latter terminates in a port e in the valve seat T. lith theparts in the positions shown in Fig. 1, the brake cylinder ducts 29, 3333a are open to an exhaust duct 34 through the medium of port c, acavity or passage m in the main valve S, and an exhaust port CZ in thevalve seat T.

A safety or reducing valve 37a is adapted to communicate through a duct37 with the valve chamber 33h; and mounted to move longitudinally insaid valve chamber is a valve 35 which, under certain cond`tions, willbe caused to engage a seat 35C and thus close communication between thebrake cylinder ducts 33- Q9 and the ducts 3T and 33a. The valve isprovided with grooves 35a in its intermediate portion to permitcommunication between the ducts 33 and 33 and to permit communication ofthese ducts with the reducing valve duct 37. The lower portion 35h, ofthe valve 35 operates as a piston in the lower portion of the valvechamber 33h, while the upper portion 35C ot' said Valve, operates as apiston in the upper portion of the valve chamber 33D. The diameter ofthe piston portion 35b of the valve 35 is I l l reservoir to the chamber3 at the v appreciably greater than the diameter of the piston portion35C of said valve, and also the greatest diameter of the seat 35e isappreciably smaller than the diameter of the piston portion 35h, t'orreasons which will be t'ully explained hereinafter. A spring 35dnormally tendsto press the valve 35 in a direction to hold it from itsseat land thus maintain (under certain conditions) communication betweenthe duct 33 and the ducts 37 and 33a.

Below the enlarged piston 35b ot the valve 35, a chamber 35f is located,and with this chamber, ducts c2 communicate. The short -ducts c2communicate with each other and with a duct c1, the latter terminatingat its upper end in an L-shaped port c in the valve seat T. A short ductg1 communicates at one end with the upper end of the valve chamber 33babove the smaller piston portion 35C of the valve 35, and at its upperend, the duct g1 communicates with a port'g in the valve seat T of themain slide valve` The seat T also contains a small port 7L which isconnected directly to the atmosphere by the duct 34. The ports g, 7L andc inthe main valve seat are controlled by the operation of the valves Rand-S, for controlling the movements of the valve 35 to effect thegraduated release ot the brakes and to cut oitl the pressure reducingvalve from the brake cylinders in the emergency application of thebrakes as more fully hereinafter described.

The main slide valve S is made with an approximately U-shaped cavity orpassage n for the purpose of connecting the ports g and /L in therelease position of the mechanism and a port t in the main valve isadapted to register' with the port c in the release position of theparts, and the cavity or passage m (in this position) connects the portsd and e.k The cavity m is made with a small extension m1 forestablishing a connection between the ports CZ and e in case the mainvalve S should travel to the right of its release position. A port /alin the main valve, is adapted to register with the port c in the seat T,and a port 791 in the main valve registers with a port b in the seat Twhen the mechanism is in service position, the port Z) being connectedby a duct 46 with the auxiliary reservoir space at the right of piston6. A port Z in the main valve registers with the port a when themechanism is in quick servicek position. A cavity or passage u in thevalve S serves to connect ports g and IL when the parts are in positionto eitect an emergency application ot' the brakes.

The graduating valve is made with a cavity or passage g adapted to fullyconnectports 7c and j) of the main valve when the graduating valve is inits extreme left hand position with reference to the main valve S, theport lo communicating with theV port. 761

and the port 20 with the port p1 for the purpose of conveying auxiliaryreservoir fluid to the brake cylinder in the service application of thebrakes. A cavity r in the graduating valve is adapted to fully connectports t2 and n2 oi the main valve When the graduating' valve is in itsextreme right hand position with reference to the main valve (the portbeing connected by a duct t1 with the port z5 and the port n2 beingconnected by a duct nl with the cavity n, for the purpose of controllingthe valve 35 to effect the graduated release of the brakes).

The valves R and S are, as before intimated, adapted to be controlled bythe movementso the piston 6, but the latter can have a movementindependently of the valve S throughout a portion of its throw, Whilethe graduating valve R is al vays movable With the piston. To provide alost-motion connection betiveen the main slide valve S and the piston 6,the rod 7 is provided .vith shoulders 25S and 39 to engage shoulders 40and 4l respectively on the valve S, said shoulders 40441 being located adistance apart which is less than the distance between the shoulders3S-39 on the piston rod 7. rl`he graduating valve R tits neatly in arecess 42 in rod 7 and is pressed to its seat on the main valve S bymeans of a spring 43, vvhich latter also serves to hold the main valve Son its seat T.

t the lett hand end ot the chamber 3, the Wall of said chamber isprovided With a` series of grooves or ducts 44 and with a groove or duct45, the latter being somewhat longer than the ducts 44 for a purposewhich Yvill hereinafter appear. lt Will be seen that When the piston isin a position at or near the lett hand end of the chamber B, the groovesor ducts 44-45 Will be uncovered so as to form by-passes for auxiliaryreservoir fluid from the space at the right or" the piston to the spaceat the left thereof and thence through ducts 44a to the valve chamber 5.When the piston reaches a position to uncover the duets 44%5, the valveS will have been so moved as to uncover the port a in the seat T, andthe auxiliary reservoir air can therefore pass through the ducts 3l-29(past check valve 32) to the brake cylinders.

Vlie duct 46, Which communicates with the right hand end of the chamber3, is extended past the port o ot' valve seat T, as shown at. 46a, andat its left hand end, the duct 46L is connected, through ducts 4T in avalve seat 4S, with a chamber 49 at the lett hand end ot the casing. Aduet 50 leading trom an emergency reservoir (not shown) alsocommunicates with the chamber 49 and communication betiveen the duets46a and 50 is normally closed by a valve 5l which is pressed to its seatby a light spring 52. The valve 5l is provided With a rod 53 which is ll i i l l l l l l i i i movable longitudinally through the seat orbushing 4S in vvhich said rod has snug lit ard the rod 53 is adaptedunder ertain conons, to be engaged by a nipple 55 at the lett end ot thepiston rod 7 for the purpose of opening the valve 5l. The nipple issecured in the end of a socket in the piston rod and through saidnipple, a rc l is longitudinally movable. rlhe rod 54 is provided(Within the socket ivith a head 54ZL against vfhich one end of a spring5G bears, the other end ot sai@` spring bearing against the end ot thesocket 55a. rlie rods 53 and are so disposed and are o1 such lengthsrelatively to each other that the rod 54 can engage the end vvall oitthe valve chamber 5 and compress the spring 56 a slight amount, beforethe nipple at the end ot' the .piston rod 7, engages the rod and opensthe valve 5l, so that a movement ot the piston,

6, through a limited distance vrill be er'lected by the action oi inespring ivhile the valve 5l remains seated, described.

litaving described the incchani ,al construction of my improvements, lWill proceed to explain the operati n cil the mechanism under variousconditions, in controlling the operation ot the brakes.` it may beassumed that the brakes have been applied, and that it is desired toetlect a graduated release. in accomplishing this, the engineer willcause a temporary rise ot' train pipe pressure by a manipulation oit` abrake valve ot any ordinary torni ot cons uction. rihe train pipepressure having been ra's xd above that in the auxiliary reservoir a siient amount to eause the piston to move to the right trom its service7or i emergency i position, said nist n vvill operate to move thegraduating an main slide valves it and S in the same direction. uringthis moveine``t r" the valves and S to the right, the p :ts ,t1 and eand p1 and o ivill be nrst disconnected and then the cavity m ivill communicate With the port e, and port will con- Aect With port c and cavitywith port it. At the same time, the piston 6 Will open or uncover thelong groove 18a at the rioht handL end ot the chamber 3. The furthermovement ol the piston G and valves l?. and S to the right will cansetle port g to tei with the cavity a and the rod 2l vvill be caused tocompress the spring 27,-the oontracted portion ot said rod,establishing` tree connnunication between the right hand side of thepiston and the auxiliary reservoir. The movement of the parts ivillcontinue until they vvill assume the positions shovvn in Fig. l, whenthe cavity m Will freely connect ports Z and e and the cavity a. Will bein full register vvith the ports o and 7i,- the port 25 being in Yfullregister with the port c. lt Will also be observed that at this time,the cavity r of the graduating valve for a purpose hereinafter willfully connect the ports t2 and a2. From the foregoing description, itwill be seen that the valve 35 will be pressed to the position shown inFig. 1, by the action of the spring 3Fd and by the pressure of the brakecylinder fluid, as the space below the large piston portion 35b of' thevalve 35 is freely and directly open to the atmosphere (through theports and passages 02, c1, c, t, t1, t2, r, n2, al, a, it and 3l) andalthough the space above the smaller piston portion 35C of valve 35 isalso directly open .to the atmosphere through the duct g1, port g,cavity n port 7L and duct 311), the cylinder pressure acting betweenthese differential pistons (35b and 35) will of' course exert a netforce in the direction of the large piston. In consequence of theseconditions, fluid from the brake cylinder will be free to pass from theducts 33 and 33a (and thence, by ports c and cl and cavity m) to theatmosphere through duct 3l, as long as the space below the piston 35b isopen to the atmosphere. This will be the case as `long as thegraduating` valve remains in the position shown in Fig. 1. lf the riseof train pipe pressure which caused the piston 6 to move to its releaseposition was only temporary (that is to say,-if after moving the brakevalve to its release or ruiming position for only a few seconds, theengineer returned it to its lap position), the pressures acting` on thetwo sides of the piston, 6, will quickly become approximately equal, asthe train pipe fluid will flow rapidly into the auxiliary reservoirthrough the ducts 13l and 18, the latter having been opened by thepiston just before reaching the end of its travel to the right. ris soonas the pressures acting on the two sides of the piston 6, thus becomeapproximately equal, the spring 27 will move the piston (through themedium of the rod 21) to the position shown in Fig. 2, thus closing orcovering the duct 13 and also causing the graduating valve R todisconnect and close ports n2 and t2 of the main valve and thereforeshut ofi the space below the piston portion 35b of valve 35 from theatmosphere. The piston portion 35b of valve 35 has a free fit in itscylinder (the lower portion of the valve chamber 33h) and thereforebrake cylinder fluid will quickly leak to the space 35f below saidpiston portion 35'). Because the upper' piston portion 35C of valve 35is still exposed on its upper side to the atmosphere, theaccumulation'of pressure below the entire area ofthe piston portion 35bwill quickly cause the valve to move upwardly; compress the spring 35land cause the valve to become seated, as shown in Fig. 2, thuspreventing the further flow of brake cylinder fluid to the atmosphere.Consequently, this position of the mechanism may be termed, its releaselap position. lf the train pipe pressure be again raised sutilcientlyabove the auxiliary reservoir pressure to cause the piston 6 to againassume the position shown in Fig. 1, the space below the piston 35b willbe again opened to the atmosphere and the valve 35 will be forced openby the spring 35d and by the brake cylinder pressure acting on the upperannular.

portion of the piston portion 35b of valve 35, (said annular portion 35gbeing formedV between the piston portion 35b and that portion of thevalve 35 which engages the'seat 35e). The valve 35 having been reopenedas above explained, a further flow of brake cylinder fluid to theatmosphere, will be permitted. It is evident therefore, that by makingtemporary increments of the train pipe pressure, the engineer can easilyeffect the graduated release of the brakes on all cars of the trainhaving this improved equipment. Furthermore, when the brake cylinderpressure becomes reduced to a very low degree, the spring 35d willmaintain the valve 35 open, regardless of the position of the graduatingvalve as it is only the action of the brake cylinder pressure inconjunction with that of the atmosphere which causes the closing of thevalve 35; consequently, any fluid leaking into the brake cylinder or itsconnecting ducts will be free to pass to the atmosphere, when, and afterthe brakes have been released in spite of the fact that the piston andgraduating valve will be removed by the spring 27 to their release lappositions as soon as the auxiliary reservoir becomes approximatelyrecharged to the normal point.

Then it is desired to make a full release (not graduated) of the brakes,it is simply necessary to restore the train pipe pressure withoutinterruption. This will, of course, hold the piston, 6, in its releaseposition; the recharging ducts (18 and 18a) being so proportioned to theexhaust ducts and ports (33, 33, r, m, Z and 34) that the completerelease of the brakes will be insured before the auxiliary reservoir canbecome recharged to its normal point. When it is desired to make aservice application of the brakes, the train pipe pressure will bereduced in the usual way and a simultaneous reduction of pressure willoccur in the controlling space through the medium of the port ln thequick service position of the valves, the port 101 will partly registerwith the port ZJ and the port /cl with the port e and port Z willregister with the port a. The graduating valve will connect ports p andla by means of the cavity g and uncover the ripper end of port Z. Thelarger portion 23 of Ythe rod 21 will restrict the port 14. Thus it willbe seen that means are provided for permitting of a flow of fluid to thebrake cylinders from the auxiliary reservoir and from the train pipe,and also that because of the restriction of port'l by the rod 21 andbecause of the fact that the fluid conveyed to the brake cylinder fromthe auxiliary reservoir must be taken trom the piston chamber 3 at theright hand side of the piston 6, through duct j port l, thuspreventin'ga further flow. of'

iluid to the brake cylinder. ll the rate of reduction of train pipepressure is slightly more rapid (than in the case just assumed), thevalves will be moved to the full service position,v when the ports p1and Y) and cl and e will be fully connected and port Z will have passedover port a. Thus a rapid llotv of luic from the auxiliary reservoir to.the brake cylinder will result, but no fluid can ilow from the trainpipe to the brake cylinder. When the desired degree of brake cylinderpressure has been obtained, the graduating valve R will (as in the quickservice i position) disconnect and close ports p and In and thus preventa further ilovv of auxiliary reservoir fluid to the brake oylinder.

`When the pressures in the auxiliary reservoir and brake cylinder becomeequal after a service application of the brakes, a reduction ot trainpipe pressure b'elovv the point necessary to aroduce this equalizationof pressures, will cause the piston 6 to move to the lett beyond itsservice positions, thus causing ports p1 and cl to be discon nected fromthe ports 5 and e and subsequently opening port u slightly and thenclosing port j". The spring-pressed rod 54 then engages the end Wall otthe chamber 5 and thus tends to prevent the further inotion ot themoving parts to the lett. During this motion the check valve 32 preventsa lioiv or fluid from the brake cylinder, through port a, to thecontrolling space. lf the brake cylinder pressure now tends to becomedepleted by leakage, fluid Will tlotv through port a to the brakecylinder from the controlling space, in which latter the pressure may bemaintained through the medium otl the train pipe if it be desired toprovide for the maintenance of the brake cylinder pressure through thatmedium, or if the train pipe pressure is lower than that in thecontrolling space, the flow of fluid from the controlling space to thebrake cylinder .vill cause the auxiliary reservoir pressure acting onthe right hand side of the piston 6 to force the latter to the left(against the resistance of the spring 56) tar enough to uncover the longgroove or duct 45 and thus permit a flow of auxiliary reservoir fluidaround the piston to supply leakage. rIhe approximate equalization otthe pressure on the two sides or the piston 6 (after the groove 45 isuncovered) together With the resistance to the further movement ot thepiston caused by the nut 55 meeting the end or rod (the latter beingpressed to the right by the high pressure of the emergency reservoirfluid acting on the lett hand side of the valve 51), will prevent thefurther movement or" the piston 6 to the lett and after the brakecylinder has been supplied in the manner just described, the spring 56Will return the piston 6 so as to close the groove 45.

In the. emergency application of the brakes, the parts will be made toassume the positions shown in Fig. 3. ln making an emergency applicationof the brakes, such a reduction of train pipe pressure 1vill be caused(by manipulation of a brake valve in the usual Way) as to cause theslide valves to be moved at once to the left, past their servicepositions, and thus opening port a (and consequently permitting a rapidflow ot lluid from the controlling space to the brake cylinder and thusinsuring the full travel of the piston 6) and subsequently closing portf. The piston 6 Will thus be forced to its extreme lett hand positionagainst the bushing 4, and thus causing the valve 51 to be unseatedthrough the medium of the rod 53 and nut 55 carried by the piston rod,and consequently permitting fluid from the emergency reservoir to flowto the chamber 3 at the right orn the piston 6. The movement ot thepiston 6 to its emergency position also causes the rod 21 to beWithdrawn from the port 14 and thus permits, at this time, a tree tloivof auxiliary reservoir fluid to the charnber 3 at the right of thepiston, and the luid from both the emergency and auxiliary reservoirs,Will flow from this space at a rapid rate to the controlling spacethrough the grooves 44-45 and duct 44a, and thence to the brake cylinderthrough the port a. The full opening of the port a by the main valveWill permit of a free tloW ot1 train pipe fluid to the brake cylinder atthis time in order to thus transmit the rapid reduction of train pipepressure throughout the train. Vlien the pressure in the controllingspace tends to become higher than that in the train pipe, the checkvalve 10 is seated by its spring and thus a back flow or fluid to thetrain pipe is prevented. l/Vhen the pressure in the emer gencyreservoir, auxiliary reservoir and brake cylinder become approximatelyequalized, the spring 56, through the medium of the rod 54, will causethe piston to move to the right tar enough to close the ducts 44 and 45,in order to prevent a flow of Fluid from the tr in pipe to the auxiliaryreservoir when it is subsequently desired to release the brakes.

During the service application of the brakes (and in all positions ofthe main slide valve between its release and emergency positions) theports c and g were closed completely, consequently the spring Bof heldthe valve 35 in its lower position (as shown in Fig. l), as there wereno connections formed to cause fluid pressure to move said valve. F orthis reason, during the service application of the brakes, the pressurereducing valve, connected to the duct 37 is obviously in freecommunication with the brake cylinders, thus providing means forlimiting the brake cylinder pressure in service applications to apredetermined degree, c., the pressure for which the reducing valve isadjusted. In the emergency position of the main slide valve, as shown inFig. 3, the main valve connects ports g and /L by Vmeans of cavity u,and consequently the space above 'the piston portion 35 of the valve 35is thus exposed to the atmosphere. As soon, therefore, as the brakecylinder pressure rises slightly, the action of this pressure on thevalve 35 will cause said valve to become seated (in spite of the lighttension of the spring 35d), and thus the pressure reducing valveconnected with the duct 37, will be cut oil from the brake cylindercompletely, as the port c is closed in the emergency position of themain valve. Thus it will be seen that the pressure in the brake cylinderis not limited in case of emergency but will rise to a high degree,depending on the sizes of the auxiliary and emergency reservoirsrelative to the brake cylinder and on the normal pressure carried in thesystem.

It will be seen from an inspection of Fig. l that when an emergencyreservoir is connected to the duct 50, said reservoir will be charged(when the pressure in it is below the normal value) with compressed airsimultaneously with the recharge of the auxiliary reservoir; fluid fromthe chamber 3 (at the right of the piston 6) passing through ducts 46,46a and 47, and, unseating valve 5l, the air will flow through thechamber 49 and duct 50 to the emergency reservoir.

Having fully described my invention what I claim as new and desire tosecure by Letters-Patent, is

l. In a triple valve mechanism, the combination with a casing providedwith a brake cylinder duct, valve devices for controlling theapplication and release of the brakes, and means for controlling theoperation of said valve devices, of a pressure reducing valve connectioncommunicating with said brake cylinder duct, a valve, and meanscontrolled by brake cylinder pressure for closing said valve to closecommunication between the brake cylinder duct and the reducing valveconnection.

2. In a triple valve mechanism, the combination with a casing providedwith a brake cylinder duct, valve devices for controlling theapplication and release of the brakes, and means for controlling theoperation of said valve devices, of a pressure reducing valve connectioncommunicating with the brake cylinder duct, a valve interposed be-`tween the brake cylinder duct and the reducing valve connection, meansfor subjecting one side of said valve to atmospheric pressure, a springnormally tending to unseat said valve, and means controlled by pressurein thebrake cylinder for closing said f'alve to close communicationbetween said brake cylinder duct and the reducing valve connection. Y

3. In a triple valve mechanism, the combination with a casing and abrake cylinder duct, valve devices for controlling the application andrelease of the brakes, and means ior controlling the operation of saidvalve devices, oli a reducing valve connection communicating with thebrake cylinder duct, a normally open valve interposed between said brakecylinder duct and reducing valve connection, means controlled by saidvalve devices t'or subjecting one side of the normally open valve toatmospheric pressure, and means controlled by brake cylinder pressurefor closing` said normally open valve to close communication between thebrake cylinder duct and the reducing valve connection.

4. In a triple valve mechanism, the combination with a. casing providedwith a brake cylinder duct, valve devices for controlling theapplication and release of the brakes, means for controlling said valvedevices, and a reducing valve connection communicating with the brakecylinder duct, of a normally open valve interposed between thebrakecylinder duct and the reducing valve connection1 means controlled byfluid Apressure in the brake cylinder duct for closing said valve toclose communication between the brake cylinder duct and reducingva veconnection, and ducts and ports controlled by said valve devices forsubjecting both sidesV oi said normally open valve to atmosphericpressure.

5. In atriple valve mechanism, the combination with a casing providedwith a brake cylinder duct, valve devices for controlling theapplication and release of the brakes, means for controlling theoperation of said valve devices, of a reducing valve connection, a ductcontrolled by said valve devices and communicating with said reducingvalve connection, a valve for controlling communication of the reducingvalve connection and said last-mentioned duct, with the brake cylinderduct, said valve having a large piston portion at one end and a smallpiston portion at the other end, said large piston portion being exposedto brake cylinder pressure, and means controlled by said valve devicesfor subjecting the free ends of said piston portions to atmosphericpressure.

6. ln a triple valve mechanism, the combination with a casing, providedwith a brake cylinder duct, a main valve and a graduating; valve, apiston for controlling` said valves, means tor subjecting one side otsaid piston to auxiliary reservoir pressure and means for subjecting theother side of said piston to train pipe pressure, of a duct controlledby said valve devices, a release valve for controlling communication ofsaid lastmentioned duct with the brake cylinder duct, said valve havinga large piston portion at one end and a small piston portion at theother end, said large piston being eX- posed on the side adjacent to thesmaller piston portion to brake cylinder pressure, means controlled bytrie main slide valve for exposing the Jree end of the smaller pistonportion of said release valve to the atmosphere, and means controlled bythe main slide valve and the `graduating valve tor exposing,- the freeend of the larger piston portion of the release valve to the atmosphere,and means for subjecting the free end of the larger piston portion otthe release valve to brake cylinder pressure,

"Y, ln a triple valve mechanism, the combination with a casing providedWith a brake cylinder duct, a main valve and a graduat` ing valve, apiston for controlling` said valves, .means Jfor subjecting` one side ofsaid piston to auxiliary reservoir pressure and means for subjecting theother' side oit said piston to train pipe pressure, ot a duct controlledby said valve devices, a release valve for controlling,` communicationoic said lastmentioned duct with the brale cylinder duct,

said valve having a large piston portion at one end and a small pistonportion at the other end, said large piston portion being exposed on theside adjacent to the smaller piston portion to brake cylinder pressure,means controlled by the main sliee valve for 'exposing the tree end ofthe smaller piston portion ot said release valve to the atmosphere, andmeans controlled by the main slide valve and the graduating` valve foreX- posing the tree end or" the larger piston portion of the releasevalve to the atmosphere,Y

and means for subjecting the tree end ot the large piston portion of therelease valve to' ing' valve, a piston for controlling said valves,means for subjecting one side ot said piston to auxiliary reservoirpressure and means for subjecting the other side of said piston to trainpipe pressure, i? a. duct controlled by said alve devices, a releasevalve tor controlling communication ot' said lastmentioned duct with thebralte cylinder duct, said release valve having,` a large piston portionat one end and a small piston portion at the other end, said largepiston being exposed on the side adjacent to the smaller piston portionto brake cylinder pressure, means controlled by the main slide valve forexposing the tree end or" the smaller piston portion ot said releasevalve to the atmosphere, means controlled by the main slide valve andthe graduating valve for exposingl the 'free end ot tne larger pistonportion of the release valve to the atmosphere, and means for subjectingthe free end or" the large piston portion o the release valve to brakecylinder pressure, and spring`- actuated n eans for moving thegraduating valve to close communication between the larger pistonportion of the release valve and the atmosphere, and means controlled bythe i'irst mentioned piston for simultaneously restricting tlze passageot train pipe fluid to the auxiliary reservoir.

ln testimony wher-eet, l have signed this specification in the presenceOt two subscribing Witnesses.

HOWARD M. l). MURPHY. Witnessesz A. N. MITCHELL, R. S. FERGUSON.

